Method of reducing replacement flywheel inventory

ABSTRACT

A flywheel capable of accommodating various automotive engines and transmission systems having different points of balance. The flywheel has a hub portion for securing to a crank shaft output arbor and a web portion integral with said hub portion on the periphery of said web portion and a weight is secured to the flywheel in such a way that the effective weight and effective position thereof is adjustable to a plurality of discrete positions, each of which is precisely correlated to each of the different points of balance of said various automotive engines having different points of balance, respectively. In a preferred embodiment, the weight is angularly and radially adjustable and is guided to each discrete position by at least one slot formed in the web, and a bolt passing through said weight and the slot. The bolts passing through the slots have safety attaching indentations therein for non-slip positive attachment of the weight in the different positions. An adaptor ring press is fitted within a hole in the hub for accommodating different output arbors of engine crank shafts and the adaptor ring and hub have cut-outs forming an elongated alignment slot for an alignment pin on the crank shaft arbor. A hole or aperture formed 180 degrees opposite the slots has an area of sufficient size as to provide a neutral balance condition when said weight means has been removed therefrom.

This is a Divisional of application Ser. No. 07/505,444, filed Apr. 3,1990 , U.S. Pat. No. 5,259,269.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates primarily to flywheels, and moreparticularly, to flywheels which are balanced adjustable so that theymay be adapted for use with a plurality of different automobile enginesand, still more particularly, the invention is directed to replacementflywheels which can be adjusted to fit a plurality of different enginesand thereby reduce parts inventories.

In heavy use, flywheels, particularly in heavy-duty vehicles such aslight trucks, taxicabs and the like, can crack or break or the ring gearteeth can wear and must be replaced with a flywheel which is balancedfor a given engine. In automotive vehicles, because of different enginedesigns, a weight is welded to the flywheel at different angular andradial positions on one surface thereof to compensate for any unbalancein a particular engine design. Because the position of this weightvaries according to engine design, replacement flywheels must have theweight in precisely the same position for balancing the engine unbalanceand, this requires a large inventory of replacement flywheels.

The present invention solves this problem by providing a flywheel inwhich the weight can be positioned at different radial and angularpositions so that one flywheel can serve 15 to 20 different enginedesigns. In a preferred embodiment, the flywheel webs are provided withmeans for guiding the weight to distinct discrete positions where theweight may be secured, in the preferred embodiment, by bolt threadablyengaged with the weight.

In a preferred embodiment, the guide means comprises one or more slotswhich are slanted relative to a radial line extending from the rotaryaxis towards the periphery of the flywheel. In the preferred embodiment,the flywheel webs are provided with a pair of slots which have aplurality of notches, with the slot connecting the notches so that theweight can be positioned in a plurality of different positions of radialand angular adjustment relative to the flywheel axis without removingthe weight from the flywheel. The slots are balanced on the oppositesides of the flywheel by removal of metal sufficient to balance theflywheel so that with total removal of the weight and screws or boltssecuring the weight to the flywheel, the flywheel is perfectly balanced.

Moreover, the arbor hole for receiving the end of the arbor on theengine crank shaft is provided with a removable reducer ring so as toaccommodate different diameters of arbor shafts. Moreover, in thisenvironment, there is constant vibration and stresses on the boltsholding the weight in position and it is possible that screws or boltsfastening or securing the weighted position on the flywheel could comeloose After mounting the weight and the bolts 41, 42 on the flywheel,the threads are damaged so that the bolts cannot be unthreaded withoutdamaging the threaded bores for the bolts and preventing reuse if thebolts are removed from the weight. Other means may be utilized forpreventing removal or unloosening of the bolt, for example, ametal-to-metal adhesive (such as an anerobic adhesive) can be used.Instead of notches, abutting surfaces of the weight and the web portionsof the flywheel on each side of a slot may be provided with interfacingor complementary notches or ribs identifying specific locations andassuring proper positioning of the weight relative to the axis of theflywheel. In such case, the ribs are provided with indicia which can becollated or correlated to the balanced position for a given engine. Ineach embodiment, indicia may be printed or inscribed on the web andweight to identify particular engine types which are balanced by theweight at a particular location. Similar indicia can be screened orinscribed on the flywheel to indicate removal of the adaptor ring.

In the preferred embodiment disclosed herein, the flywheel is of thetype used with automatic transmissions which includes a conventionaltorque converter which provides the basic inertia for the engine. Whilethe preferred embodiment disclosed herein relates to flywheels for usewith torque converters in an automatic transmission, it will beappreciated that the basic invention may also be applied to balancinginternal combustion engines with manual transmissions wherein theflywheel may be a heavy iron or steel casting and includes a clutchmechanism associated therewith.

Accordingly, it is a basic object of this invention to provide anadjustable flywheel for automotive engines.

Another object of the invention is to provide an adjustable flywheel forautomotive engines which eliminates the need for inventorying largenumbers of different flywheels for different engine/transmissioncombinations.

Still another object of the invention is to provide a method of reducingthe inventory requirement for replacement flywheels for various internalcombustion engines having different points of balance wherein theflywheel is provided with one or more weights releasably fastenedthereon and adjusting the weight by means of unfastening one or moreweights so that the flywheel has points of balance corresponding todifferent points of balance of various internal combustion engines,respectively. Another object of the invention is to provide areplacement flywheel capable of accommodating various automotive engineshaving different points of balance wherein it is possible to adjust theflywheel to fit many engines. A further object of the invention is toprovide a flywheel with a center adaptor to make it possible for theflywheel to fit many engines with different arbor diameters.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the inventionwill become more apparent when considered with the followingspecification and accompanying drawings wherein:

FIG. 1 is a schematic side elevation view of an internal combustionengine, flywheel and torque converter, incorporating the presentinvention,

FIG. 2 is a sectional/isometric view of a flywheel incorporating theinvention,

FIG. 3A, B, C . . . N diagrammatically illustrates how the flywheel ofthe present invention is able to adapt and accommodate a plurality ofdifferent engines A, B, C . . . N,

FIGS. 4 is a plan view of a flywheel incorporating the invention.

FIGS. 5A, B, C . . . N illustrate various discrete positions ofadjustment of the removal of the annular knock-out to accommodatevarious engines,

FIG. 6 is a diagrammatic illustration of the central hub and web portionof a flywheel incorporating the invention showing exemplary measurementsthereon,

FIG. 7 is an enlarged sectional view through one of the bolt/fastenersshowing the upsetting of the end thereof,

FIG. 8 is a modification of the preferred embodiment,

FIG. 9A is a sectional view of a further embodiment of the invention;FIG. 9B is a plan view showing the guide slot in the weight; FIG. 9C isan embodiment of the invention wherein the discrete weight positions aredefined by bolt holes, and

FIGS. 10A, 10B, 10C and 10D illustrate a further embodiment of theinvention wherein the weight is crescent or moon-shaped and there arethree guide slots.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a typical engine flywheel transmission combinationincludes an engine 10 with a crank shaft 11 therein having an outputarbor 12 bolted (TB) to flywheel 13 which, in turn, is bolted (TCB) to atorque converter 14 which has an output shaft 15 leading to the drivenload. As diagrammatically illustrated in FIG. 3 the engine 10 isindicated as the crank shaft 16 of a 4-cylinder engine. The crank shaftis supported by main bearing journals 17 and 18 (there may be a timinggear wheel, not shown, connected to the end 18 of the crank shaft) andconnecting rod bearing journals 19, are also provided. The crank shaftincludes counter weights 20 which impede the centrifugal force of theconnecting rod assembly attached to the bearing supports and tiestogether the reactions of the pistons and connecting rods transformingthe reciprocating motion into rotary motion and transmits the enginepower through the flywheel torque converter or transmission to thedifferential to drive a vehicle, for example.

As diagrammatically shown in FIG. 3, a weight W may be welded to theflywheel to compensate for an unbalance in a particular engine design.Of course, if the engine is well balanced, no weight is used. In allcases, when the flywheel must be replaced, it must be replaced with aflywheel which is balanced by a positionally located weight for a givenengine and this position of balance may vary from engine-to-engine.Flywheels according to the present invention can be adapted toaccommodate large numbers of different engines and thus reduce theexpense of inventorying a large number of different flywheels fordifferent engines.

Referring now to FIGS. 2, 4 and 6, the flywheel 25 is constructed foruse with an automobile internal combustion engine having an automatictransmission but it is to be understood that the invention is applicableto other engine configurations and to engines having a clutch. Theflywheel 25 incorporates a central disk portion which is a round,relatively flat stamped metal plate having a hub portion 28 and a webportion 26. The engine side of the flywheel 25 is facing the viewer. Aring gear 27 is welded to the outer periphery of web 26, gear 27 havingteeth 27T around its entire circumference which engage pinion gear teethon a starting motor (not shown).

Hub portion 28 is provided for mounting the flywheel on the arbor end 12(FIG. 1) of an engine using arbor mounting bolts AMB which pass throughmounting bolt holes 29. Since the crank shaft arbors may have differentmounting bolt positions, overlapping holes 29a, 29b provide forattachment to a wide range of engine arbors.

In addition, typically an engine crank shaft arbor may have a guide pin,diagrammatically illustrated at GP, which may likewise vary fordifferent engines and an elongated slot 30 is provided to accommodatedifferent engine guide pins GP.

Engine crank shaft arbors may vary in diameter and to accommodatedifferent diameters, an adaptor ring 35 is press-fitted within hub holeHH and may be removed to accommodate different output arbors of enginecrank shafts. As shown in FIG. 2, the adaptor ring 35 has a small flangeor rim AR which prevents it from being pushed through arbor hole HH. Asshown in FIG. 4, the end of slot 34 is extended into the outer peripheryof adaptor ring 35 to accommodate, for example, a arbor-orienting pinGP, shown in dotted in FIG. 2. The web 26W and hub 28 are made of a mildcarbon steel stamping and a hardened steel ring gear 27 is welded to theperiphery of the web 26.

Large diameter holes 26H provide access, and the securement of the webto the torque converter is by means of bolts TCB passing through holesTCB in offsets OS, the torque converter being located on the oppositeside of the flywheel as depicted in FIG. 2.

A weight 40 is adjustably secured to the flywheel web and is adjustableto different angular and radial positions on one surface thereof tocompensate for any unbalance in a particular engine design. As shown inFIG. 7, hex head bolts 41 (and 42) pass from the torque converter sidetowards the engine side and are threadably engaged with threaded bores40TB in the weight 40. As best shown in FIG. 6, a pair of guide slots 50and 51 are formed in web 26 during the stamping thereof and guide a pairof hex head bolts 41, 42 to precisely position weight 40 in a pluralityof different positions of radial and angular adjustment relative to therotary axis of the flywheel. These slots 41 and 42 are balanced on theopposite side of the flywheel by an aperture 43 in which sufficientmetal is removed to balance the metal removed to form the slots so thatupon total removal of the weight 40 and the bolts 41, 42 securing theweight to the flywheel, the flywheel is perfectly balanced (see FIG.5N).

As shown in FIG. 7, hex head bolt 41 has the outer end thereof indentedand/or otherwise upset as at 45 to cause the lateral circumferencecircumferential edges thereof 46 to flare outwardly to prevent removalof the bolt 41 without damaging the threads in threaded bore 40TB. Thisis a safety feature in two senses: In this environment there is constantengine vibration and stresses on the bolts holding the weight inposition and is possible for these bolts fastening or securing theweight in the predetermined position on the flywheel could come looseafter a period of time and the mounting weight and the threads beingupset to prevent them from becoming loose. It also prevents the mechanicfrom removing and reattaching the weight or a different weight unless itis desired to totally remove the weight from the flywheel to balance theflywheel per se.

As shown in FIG. 6, the end positions of slots 50 and 51, formingnotches 50N1 and 51N1, define one position of adjustment for the weight,notches 50N2 and 51N2 define a second position of adjustment which isboth radially and angularly different from the position 50N1, 51N1 and,similarly; and notches 50N3 and 51N3 define a further position ofadjustment. It will be obvious that a larger or smaller number ofpositions can be used than the three illustrated (see in FIG. 8, forexample). These combinations of positions of adjustment, with the arboradjustments discussed earlier herein allow this embodiment of theflywheel to accommodate a multitude of different engines with differentpositions of balance thereby reducing the inventory requirements ofparts suppliers. In addition, it allows original equipment manufacturersto provide one flywheel design which can accommodate a large number ofdifferent engine designs thereby simplifying their productionrequirements and improving efficiency and reducing costs.

Referring to FIG. 5, four exemplary engine balance conditions are shown.In FIG. 5A, the arbor adaptor ring 35 is in place and weight 40 isbolted in place in slot notches 50N3 and 51N3. In FIG. 5B, the arboradaptor 35 has been removed and the weight secured or bolted in aposition defined or located by slot notches 50N2 and 41N2. In FIG. 5C,the arbor adaptor is in place and the weight 40 is bolted in theposition defined by the bolt shafts in slot notches 50N1 and 51N1. Notethe angular and radial positions of the weight 40. In FIG. 5N, theweight and the bolts have been removed and the flywheel is perfectlybalanced.

It will be appreciated that in addition to bolting the weight at thedifferent positions, a metal-to-metal adhesive such as an anerobicadhesive may be utilized to or in addition to the bolt.

It will be appreciated that if the safety feature described above inconnection with the upsetting the end of the fastening bolts is notdesired, this may be eliminated.

As diagrammatically illustrated in FIG. 8, a single slot 60 may beutilized in conjunction with means for defining precise positions alongthe slot 60 for precisely positioning the weight at different positionsof radial and angular adjustment. In this case, a round or circularweight 61 is utilized and annular ribs or grooves 62 formed in the web26' and complementary grooves 63 in the weight 40' (see FIG. 9A) providepositive locking of the weight in the different positions of adjustment.It will be appreciated that the slot may be a radially extending slot inwhich case no angular adjustment is incorporated into the weight.Moreover, as shown in FIG. 9B, the slot CS can be curved and formed inthe weight 40' and with a securement bolt SB, having the ends upset inthe manner illustrated in FIG. 7, will be threadably engaged with athreaded bore hole in the web of the flywheel 26'. In the embodimentillustrated in FIG. 9C, the discrete positions are defined by the boltholes 50BH-1-51BH1, 50BH-2-51BH2 and 50BH-51BH. In this case, the endsof the bolts may be upset after they have been threaded through theweight.

In the embodiment shown in FIG. 10A, B, C and D, which is particularlyadopted for Ford-type engines, the weight 40" is crescent or moon-shapedand web 26W' has three guide slots 80, 81 and 82, which interconnectdiscrete notch positions 80N1, 80N2 and 80N3, 81N1, 81N2 and 81N3, and82N1, 82N2 and 82N3, respectively and, which guide three bolts 100, 101and 102 to the respective notch positions. As in the embodiment shown inFIG. 9C, the discrete positions can be established by bolt holes withoutthe slots interconnecting same. Numerals corresponding to previouslydiscussed features are primed. In FIG. 4D, the weight 40" has beenremoved and is perfectly balanced. In FIG. 4A, weight 40" has been movedradically outwardly to the position defined by notches (or bolt holes)80N3, 81N3 and 82N3. In FIGS. 10C and 10D, the weight has been angularlyshifted to positions defined by notches 80N1, 82N1 or 80N2, 81N2 and islocated inwardly of the rotary axis.

It will be noted that the weight in the preferred embodiment has anouter periphery that has a curvature that is precisely the same as thecurvature of the inside rim of the ring gear RG.

While there has been shown and described a preferred embodiment of theinvention, it will be appreciated that various modifications andadaptations and variations of the invention can be made withoutdeparting from the spirit and scope thereof and it is intended toencompass such obvious modifications and adaptations as come within thescope of the accompanying claims.

What is claimed is:
 1. A method of reducing the inventory requirements for replacement flywheels for various internal combustion engines having different points of balance, comprising providing a replacement flywheel having an arbor mounting hub and at least one weight means releasably fastened thereon, and a press fit arbor ring in said arbor mounting hub, adjusting said weight means by unfastening said at least one weight so that said replacement flywheel has predetermined points of balance corresponding to different points of balance of said various internal combustion engines, respectively; and selectively removing said press-fitted arbor ring to adapt said arbor mounting hub to said internal combustion engine.
 2. A method of reducing the inventory requirements for replacement flywheels for various internal combustion engines having different points of balance comprising providing a placement flywheel having one or more predetermined weight means releasably fastened thereon and adjusting said weight means by securing or removing said one or more weight means at predetermined positions so that said flywheel has predetermined points of balance corresponding to different points of balance of said various internal combustion engines, respectively.
 3. A method of reducing the inventory requirements for replacement flywheels for various internal combustion engines having different points of balance, comprising providing a replacement flywheel having at least one weight releasably fastened thereon and adjusting said weight angularly to predetermined positions corresponding to different points of balance of each of said various internal combustion engines, respectively.
 4. The method defined in claim 3 including radially adjusting the position of said weight to correspond to said different points of balance. 